Image-projector.



W. SAMS.

IMAGE PROJECTOR.

APPLIOATION rILED JULY 8,1912. RENEWED APR. 1o, 1914.

2 SHEBTSSHEET l.

Ptente Nov. 17, 1914.

MllllllllHU HH H W. SMS.`

IMAGE PROJECTOR.

APPLICATION FILED JULY 8,1912y RENEWED APB.10,1914. 1,1 17,252. PatentedNOV.17, 1914.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

WALTER SAMS, 0F CHICAGO, ILLINOIS.

IMAGE-PROJECTOR.

Specication of Letters Patent.

Application led July 8, 1912, Serial No. 708,132. Renewed April 10,1914. Serial No. 831,046.

To all whom it may concern:

Be it known that I, WALTER SAMS, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Image-Projectors, ofwhich the following is a full, clear, concise, and exact description,reference being had to the accompanying drawings, forming a part of thisspecification.

My invention relates to image projecting apparatus and has beenspecifically embodied in a stereopticon, though the invention is not tobe limited to such an embodiment.

My invention, in its specific aspect, re-

i lates to those image projecting devices that employ electric lamps andhas for an 0bject such a location and formation of the resistanceemployed to adapt the lamps to line voltages as to enable suchresistance to act as light shields to prevent the undue escape of light.It is to be understood, however, that my invention is not to be limitedto image projecting devices that employ electric lamps, in allembodiments of the invention.

My invention'has for another of its objects the provision of improvedmeans for leveling the image with respect to the field upon which it isto be projected. The invention has for another of its objects animprovement in the construction of the telescoping members whereby thelenses and lamps may be depressed so that the alinement of theseelements with respect to the images that are to be projected may be dulymaintained.

The invention has for a further object the provision of improved meansfor limiting the extent.` to which the telescoping elements may be\-drawn apart.

y I will explain my invention more fully by reference tothe accompanyingldrawings showing the preferred embodiment thereof and in which- Figure1 is a view in side elevation of a stereopticon constructed inaccordance with the invention; Fig. 2 is a plan view of the structureshown in Fig. 1, circuit connections being added when the device is tobe used in connection with an electric circuit.`

for furnishing light; Fig. 3 is a longitudinal elevation, mainly insection, of the structure; and Fig. 4 is a View in front elevation ofthe structure.

Like parts are indicated by similar characters of reference throughoutthe different figures.

The structure includes a mounting base l that supports a shaft 2 whichis rotatable in the mounting base about a vertical axis, this shaft 2being bifurcated at its upper end to alord a vertically disposed recessin which it receives the tongue 3 of a. shaft 4, the tongue beingrotatable about a horizontal axis alorded by the pin 5 passing throughthe bifurcated portion of the shaft 2 and the tongue 3, whereby themachine may be adjusted with respect to the field upon which it is tocast the image. The shaft 4 has two holes passing therethroughlongitudinally of the machine and through which pipe sections 6 and 7pass and in which said pipe sections are preferably movablelongitudinally of the machine while at the same time they are fixed withrespect to cach other, a yoke 8 being employed for this latter purpose.Pipe sections or telescoping members 9 and 10 are intelescopic relationwith the members 6 and 7 and are themselves rigidly held with respect toeach other by means of yokes 11 and 12. The yoke 12 is verticallyextended upwardly and supports, at its upper end, a source of light 13which, in the embodiment of the invention herein shown, is an electriclamp employing separated carbon pencils between which a lighting arc maybe established, though I do not limit myself to the employment of anelectric lamp in all embodiments of my invention nor to an electric lampin the form of arc lamp in the particular embodiment of the inventionillustrated. It is customary to connect the lamps, when they are in thef'orm of electric lamps, in bridge of supply conductors and in suchevent the lamp bridge is to include a resistance to reduce the voltageto that required by the lamp. Such a resistance is shown at 14 in Figs.2 and 3 and is in the form of a suitable resistance wire that isproperly' projection of the images is prevented, the bore of thecylinder or tube being of suficient size to permit of the passage ofsufficient light therethrough. To secure the best results the compositeresistance and light shield 14, 15 is located immediately in front oftheilamp 13 and immediately behind the lens mount 16, the light shieldfilling the space between the lamp and the lens mount, though I do notlimit myself to this location of the light shield. Further to guardagainst the escape of light rays, the cylinder 15 is provided with anannular shield 17 that closes the annular gap between the lens mount 16and the element 15, a second annular shield 18 being located between therear of the element 15 and the lamp structure so as to close the annulargap intervening between the elements 13 and 15. The element 15 may besupported in any suitable way, it being shown as being mounted upon theupper end of the yoke 8 in the embodiment of the invention illustrated.The lens mount 16 supports the usual or suitable condensing lenses 19,20.

A slide guide 21 is mounted in Afront of the lenses, this guidereceivingan image holding slide 22 that is employed for holdin the images thatare to be projected upon a held. In the embodiment of the inventionillustrated the image holding slide 22 is adapted to receive glassplates upon which the images to Abe projected are provided. Thecondensinglens mount 16 is provided with an annular cap 23, and as thelens' mount and lens cap are both cylindrical and of closelyapproximated diameters, the cap may be turned upon the mount,longitudinal separation of the cap and mount being prevented byinsetting engaging annular beads 24, 25 provided upon the cap and mountas illustrated in Fig. 3. Four segments of the peripheral portion of theannular cap 23 are struck outwardly to form spring fingers as indicatedat 26, at once forming a space through the cap 23 in which the imageholding slide may be moved transversely through the cap and springlingers for engaging the slide guide 21 and yieldingly' mounting thesame in normally fixed position with respect to said cap. The level ofthe image may be adjusted without changing the relationship between thecap 23 and the slide guide 21 merely by turning the cap 23 upon the lensmount 16.

. The structure illustrated includes an objective lensl whose mount 27is su ported at the upper' end of' a yoke 28, this yoke 28 being inrigid relation with two telescoping members or rods 29, 30 that are intelescoping relation with the rods 6 and 7. The objective lens may beadjusted forwardly and rearwardly by moving the hollow rods 29, 30 outand in. Additional rods 31 and 32,

united by a yoke 33,`may 4be interposed between the rods 29 and 30 andthe rods 6 and 7 and, further, rods 34 and 35, united by a yoke 36, maybe interposed between the rods 31 and 32 and the rods 6 and 7. Theforward ends of the rods 6 and 7 may be unlted by a yoke 37 further tohold these two rods in rigid relation. I do not limit myself to thenumber of telescoping rods that are interposed between the objectivelens and the main telescoping rods 6 and 7. The extent to which one pairof rods in telescoping engagement with another may be drawn apart islimited by a chain or other flexible or collapsible connectionintervening between the yokes of such rods. Thus, in Figs. 1 and 3, I'have illustrated a collapsible connection 38 between the yokes 28 and33, a collapsible connection 39 between the yokes 33 and 36, and acollapsible connection 40 between the yokes 36 and 37, these connectionsbeing sufficiently short to prevent the4 complete disengagement of thetelescoping members while at the same time allowing them to besufficiently extended to suit the range of adjustment for which thetelescoping members are provided. By the mechansim illustrated the lamp13 may be adjusted without fear on the part of the operator that it willbecome dismounted. I consider the flexible connections which have beendescribed broadlv to be new with me irrespective of the construction andarrangement of the telescoping members.

It will be observed that the telescoping members are arranged in twosets, the set 6, 9, 29, 31 and 34 overlying the set 7, 10, 30. 32 and35. By this arrangement the objective lens may be placed in its foremostposition and the lamp 13 may be placed in its rearmost position withoutdanger of disturbing the alinement of the lamp, the condensing lensesand the objective lens, since the flexure in a vertical lane of thesupports for the objective ens in the lamp structure is guarded againstbecause of the superimposition of one set of telescoping elements abovethe other. I am aware that it was hitherto the practice to locate bothsets of telescoping elements side by side in a horizontal plant, but itwill be obvious that such an arrangement of the prior art will notaccomplish the result which is accomplished by the arrangement of thesets of telescoping elements herein disclosed.

While I have herein shown and particularly described the preferredembodiment of my invention I do not wish to be limited to the precisedetails of construction shown as changes may readily be 'made withoutdeparting from the spirit of the invention, but

Having thus described my invention I claim as new and desire to secureby Letters Patent the following izo 1. An image projectorincluding anelectric lamp; a lens element in the path of light emanatin from thelamp; and a resistance element` or inclusion in circuit with the lampand constituting a li ht shield along which light rays from the amppass.

2. An image projector including an electric lamp; a. lens element in thepath of light emanating from the lamp; and a resistance element oftubular formation for inclusion in circuit with the lam and constitutinga light shield through w ose bore light rays from the lamp pass.

3. An image projector including an electric lamp; a condesing lenselement in the path of light emanating from the lamp; and a resistanceelement of tubular formation for inclusion in circuit with the 1am andconstituting a light shield through whose bore light rayaA from the lamppass, the light shield being interposed between the lamp and thecondensing lens element.

4. An image projector including an electric lam a condensing lenselement in the path of ight emanating from the lamp; and a resistanceelement for inclusion yin circuit with the lamp and constituting a.light shield along which li ht rays from thelamp pass, the hght shielbeing interposed between the lamp and the condensing lens element.

In witness whereof, I hereunto subscribe my name this lifth day of JulyA. D. 1912.

WALTER SAMS.

Witnesses:

E. L. WHITE, G. L. CRAGG.

